COMMENT ⊗   VALID 00002 PAGES
C REC  PAGE   DESCRIPTION
C00001 00001
C00002 00002	This file lists changes to the METAFONT manual, occurring since its publication
C00011 ENDMK
C⊗;
This file lists changes to the METAFONT manual, occurring since its publication
as a Stanford report in 1979 (which is the same as the version published by
Digital Press in December 1979). The programs and font specifications in
Appendix E have been thoroughly revised, and report CS780 ("The Computer Modern
Family of Typefaces") shows the current version; however, some
significant changes to that appendix are listed below.

Page 4, line 8, TEX should have been told not to break at that hyphen!

Page 24, line 6, change "$h↓0$ units high," to "$l↓0$ units high, where $l↓0$ is
the current value of lpenht,"

Page 24, line 12, change it to "lpenht 25; rpenht 25;"

Page 28, table, change $h↓0$ to $l↓0$ in the lpen column and to $r↓0$ in the
rpen column

Page 48, table, change $h↓0$ to $l↓0,r↓0$ in the lpen,rpen column

Page 53, line 8, change (x+1,y) to (x,y+1)

Page 61, insert a new "dangerous bend" just before Chapter 9:
METAFONT has a limited memory available for storing subroutines. If you know
that some subroutine, say "s", is no longer going to be needed, you can remove
it from METAFONT's memory by writing "subroutine s:.".

Page 61, fifth line of Chapter 9, change "points" to "point" and "signs" to "sign"

Page 65, lines -9 and -8, change to:
hpenht, vpenwd, lpenht, and rpenht (normally 1) are used
to specify the height of each hpen, the width of each vpen, the height of
each lpen, and the width of each rpen. It is best...

Page 66, lines 14-19, change to:
crsbreak specifies a $y$ coordinate at which a tall character will be
broken into pieces when preparing it for an Alphatype CRS font. If you specify
several different crsbreaks for the same character, it will be broken into
several different pieces. At most 1020 nonzero rows of the raster should appear
between breaks.

Page 66, line -4, change "and penreset" to "penreset, and points"

Page 67, lines 8-10, change "from ... to ..." to "between ... and ..., inclusive"

Page 67, line -12 (re penreset), change "begins." to "begins or a section ends."

Page 67, before line -11, insert:
points  causes METAFONT to display labeled points in proof mode.

Page 67, line -9, change "These" to "If points is turned on, these"

Page 67, lines -6 thru -4, delete "Thus you ... section."

Page 74, a new error message:
! lpen height too small, set to 1.
You shouldn't try to make lpenht less than 0.5. Proceed, and it will be set to 1.

[A similar message about rpenht goes on page 77, and the wording of the similar
messages for hpenht and vpenwd should be shortened to match.]

Page 74, new types of overflow:
brksize,	number of crsbreak points in a character;
initblocks,	number of preamble blocks in binary font file

Page 77, a new error message:
! Square root of -<constant>, replaced by 0.
You tried to take the square root of this negative number. Proceed, and its
value will be zero.

Page 84, line 5, interchange "height" and "width"

Page 85, line 14, change 37/23 to 23/37

Page 87, bottom line, "c ↔ px" should be "m ↔ px"

Page 88, lines 2-3, change "Fortunately ... x-height." to:
Variable  m  is used to stand for the x-height, since a line at this height is
traditionally called the "mean line."

Page 88, line 6, a "c" is in row c →→ an "m" is in row m
(and so on, changing c to m in lines 7 and 8)

Page 88, line 7, change "pixel ... appears" to "pixels ... appear"

Page 88, lines -9 through -5:
w8, the curve height;
w9, the upper-case stem height.
Note that the last four of these variables have no "p-variable" equivalent; they
satisfy the approximate relation
w6/w0 \approx w7/w1 \approx w8/w2 \approx w9/w4 \approx aspect.
The hpenht, lpenht, and rpenht are $w↓6$ and...

Page 90, lines 16-19 of Figure E-2 should be indented

Page 91, lines 12 and 16 of Fig. E-3, change "counter" to "bowl"

Page 91, line -11, a "W" too. →→ "M" and "W".

Page 92, lines 5 and 17, change c to m

Page 92, lines 12-15, change to:
w6=round(pixels.pw.aspect+blacker);
w7=round(pixels.pwi.aspect+blacker);
w8=round(pixels.pwii.aspect+blacker);
w9=round(pixels.pwiv.aspect+blacker);
hpenht w6; vpenwd w0; lpenht w6; rpenht w6;

Page 92, line 23, change "3pu,3pu" to "3pu,2pu"

Page 92, line -2, delete "charic italcorr", also delete line -1

Page 93, lines 1-8, change to:
tu=pu.pixels; uw=charuw-sc.(lftcorr+rtcorr);
if fixwidth=0: moduw=uw;
else: moduw=9; new italcorr; italcorr=0;
fi;
r=charuw.u=round((moduw.tu-2).charuw/uw);
charic italcorr; charwd moduw.pu; chardw moduw.tu;
incx round(-sc.lftcorr.u);
if mode=0: call box(round sc.lftcorr.u);

Page 93, line 10, "guidelines"

Page 93, line 19 should be "y5 = y6 = m; draw 5..6; % mean line (x-height)"

Page 96, change "ru" to "pu" in 8 places

Page 96, line -8, change "`ff" to "``ff".

Page 96, line -13, change "example" to "particular example"

Page 99, lines 1-4, change the sentence to read as follows:
If this is not zero, it denotes the amount of space in points whose multiples
will be used for all spacing in math formulas: the otherwise-specified
conventions for thin space, thick space, \mskip, etc., will be changed so that
there is no streching or shrinking, and the amount of space will be increased in
magnitude if necessary to make it a multiple of the math space.

Page 102l, add p. 72 under "hpenht".

Page 102r, first page for crsbreak should be 66, not 67

Page 102r, new index entries:
$l↓0$, 24, 28, 48.
{\bf lpenht}, 24, 65, 74, 88.

Page 104l, new innex entries:
$r↓0$, 28, 48.
{\bf rpenht}, 24, 65, 77, 88.

Page 104r, new index entry: {\bf subroutine}, 55.

Page 104r, add p. 80 under "vpenwd".